Magazine latching means for stapling machines



Oct. 4, 1955 H. w. MARANO 2,719,296

MAGAZINE LATCHING MEANS FOR STAPLING MACHINES Original Filed Feb. 17,1953 3 Sheets-Sheet 1 THE .1.

' lNVENTOR #523527- M M/IE/l/VO ATTORN EY Oct. 4, 1955 H, w, MARANQMAGAZINE LATCHING MEANS FOR STAPLING MACHINES 3 Sheets-Sheet 2 OriginalFiled Feb. 17, l955 [NW l NIH]? h. Mnemm ATTORNEY Oct. 4, 1955 H. w.MARANO MAGAZINE LATCHING MEANS FOR STAPLING MACHINES Original Filed Feb.17, 1953 5 Sheets-Sheet 3 INVENTOR HERBERT M M/rm/va BY 2 ATTORNEYUnited States Patent O MAGAZINE LATCHING MEANS FOR STAPLING MACHINESHerbert W. Marano, Summit, N. ,L, assignor to- Wilson Jones Company,Chicago, Ill., a corporation of Massachusetts Original applicationFebruary 17, 1953, Serial ,No. 337,328. Divided and this applicationDecember 9, 1953, Serial No. 397,125

11 Claims, (Cl. 1---49) The present invention relates generally to animproved fastener driving device, and it relates in particular to animproved portable, hand-operated device which will drive a singlefastener such as a staple, or the like, from a pre-formed cohered stripof such fasteners into wood, cardboard, plastic or other materials. Theword staple as herein used will indicate fasteners of that general type.

This application is a division of application Serial No. 337,328, filedFebruary 17, 1953.

Hand-operated stapling machines of the general type with. which thepresent invention is concerned are widely used, and consist generally ofa spring-loaded plunger or ram having a depending staple-driving bladernovable along a predetermined path, a magazine for holding a strip ofstaples with the foremost staple in the path of the driving blade, and ahand-operated mechanism for retracting and releasing the spring-loadedplunger whereby to effect the staple driving stroke.

The conventional heavy duty stapling gun of the aforementioned type is ahighly inefiicient machine, inflexible, expensive to fabricate, subjectto excessive wear, 1. .6 difficult to operate and service. Theinefficiency of the conventional gun tacker has been found to bedirectly attributable to the eccentricity existing between the line. offorce of the energy storing plunger driving spring and the line of forceexerted by the plunger retracting and spring loading element. The torqueimparted to. the plunger as a result of this eccentricity accounts for am j P t o e e e gy xpe d in a ngv t e vi g spring and is dissipated infrictional losses, which in turn greatly contribute to the excessivewear of the stapling device and demands an expenditure of much moreenergy on the part of the operator than should be necessary in employingthe stapling gun.

Another disadvantage encountered in the conventional gun tacker is itslimitation to use with only one size staple, or its limitation within anextremely small range of sizes. The spring loading and actuatingmechanism is such that the energy stored in the spring during eachdriving stroke is normally fixed and unalterable. The gun tackerrequires a major conversion in order to readjust or change the amount ofenergy stored in the driving spring during the stapling cycle. Thedrawbacks of this construction are readily apparent in view of the factthat it is often desirable toswitch from one size staple to another andto apply the staples to different types of materials. Moreover, theoptimum drive applied to the staples varies with the staple size and thematerial to which they are applied, and conventional devices make noprovision for varying readily the driving force. Another undesirablecharacteristic of the conventional gun' tacker is the tendency of thestaples in the magazine to jam. The guide which accommodates the stripof staples has upper confronting walls which are, of necessity, spacedat distance at least as large as the greatest diam.- eter of the wireformingthe staples. Since the diameter of this wire varies, it oftenhappens that the staple strip pusher causes staples of lesser diameter.wire to mount each other and jam the guideway. Increasing the strengthof the pusher spring is of no help since it merely further aggravatesthe jamming.

Typical of the difficulties met in the manufacture of the conventionalgun tacker is the fabrication of the staple exit guide. This guide,being subject to the maximum wear and abrasion, must be heat treated forreasonable service. However, since this guide is generally formedintegral with the lower channel member of the gun tacker, its properhardening without disturbing the channel member is a major problem anddiflicult of proper attainment without a large percentage of rejects,There are many other drawbacks and disadvantages encountered in theconventional staple gun tacker in spiteof the fact that this device isuniversally and widely employed, and much efiort has been expended inits development.

It is, therefore, a principal object of the present inven tion toprovide an improved fastener driving device.

Another object .of the present invention is to provide an improvedportable hand-operated staple gun tacker.

Still another object of the present invention is to provide an improvedstaple gun tacker requiring a minimum of manual effort in its operation.

A further object of the present invention is to provide an improvedstaple gun taeker having a staple driving mechanism which is highlyefiicient in the transmission of the energy expended by the operator inrelation to the driving of the staple.

.Still a further object of the present invention is to provide an.improved staple gun taclcer which is capable of handlingstaples of alarge range of sizes.

Another object of the prcsent'invention is to provide an improved staplegun tacl'ger in which the force imparted to the staples may be easilyand simply manually adjusted.

Still another object of the present invention is to provide an improvedmagazine for the strip of cohered staples in which the jamming of thestaples is eliminated. A further object of the present invention is toprovide an improved staple gun tacker having a staple loading mechanismwhich permits the rapid and simple insertion of. a strip of staples.

Still a further object of the present invention is to provide animproved staple gun tacker having a novel staple exit channel whichgreatly facilitates the fabrication thereof. I The above and otherobjects of the present invention will become apparent from a reading ofthe following de: scription taken. in conjunction with. the accompanyingd w ng whe n Figure 1 is an exploded view illustrating in perspectivethe. various. components entering into the assembly of an improvedstaple gun tacker in accordance with the present i enti n;

Figure 2 is a side transverse sectional view of the staple gun tacker inuncocked condition;

Figure 3 is a side transverse sectional view of the forward portion ofthe staple gun tacker in fully cocked condition immediately precedingthe release of the staple driving plunger;

Figure 4 is a side detail view, partially in section and partiallybroken away, of the staple magazine and opening and loading mechanismillustrated in open position;

Figure 5 is a side elevational view of the improved staple gun tacker.in normal uncooked operative posiion;

Figure 6 isaside elevational view of the tacker showing the handle inthe magazine opening position;

Figure 7 is. a sectional view taken along line 77 of A Figure 2 showingthe driving force adjusting element in the high energy position;

Figure 8 is a sectional view taken along line 88 of Figure 3 showing thedriving force adjusting element'in the low energy position;

Figure 9 is a sectional view taken along line 9--9 of Figure 2;

Figure 10 is a sectional view taken along line 10-10 of Figure 2; and

Figure 11 is a sectional view taken along line 1111 of Figure 2.

A staple gun tacker embodying features of the present invention includesa main body or frame member having an actuating handle hinged to itsupper front edge, a staple magazine housing hinged to its lower rearedge and a channel shaped member secured to its front and defining ahousing and guide for the staple driving plunger and spring. Slidablysupported in the front channel is a plunger or ram having a horizontalshoulder and a depending driving blade which rides along the inner frontface of the channel. An energy storing compression spring is confinedbetween the upper face of the ram shoulder and a vertically spaced shelfand urges the plunger to its lowermost or advanced position. The plungercocking and releasing mechanism comprises a horizontally hinged liftinglever whose free end engages the bottom face of the ram shoulder at apoint colinear with the line of force of the ram driving spring, thelever having a longitudinal slot formed therein. A fulcrum is pivotallymounted in the upper part of the frame member and supports at its frontend a depending cocking member terminating in a pointed end topped atits forward edge by a recessed portion defining a hook above which theedge inclines rearwardly defining a cam surface. The cocking memberregisters with the lifting lever slot, the hook normally engaging thefront edge of said slot. The rear end of the fulcrum is link-connectedto the actuating handle.

A vertically stepped triggering element is slidably supported by theframe in confronting relation to the front edge of the cocking member sothat different portions of the trigger may be brought into alignmentwith the cocking element whereby to trigger the cocking mechanism atpreselected points in its stroke and hence impart varying driving forcesto the plunger as will be described in detail. A channel shaped stapleguide is disposed on the base of the magazine housing and engages aslidable staple pusher which is urged forward by spring means. Anelongated staple retaining element is hinged at its rear to the lowerportion of the frame at point intermediate the ends of the frame andterminates at its front end in depending rearwardly facing hooks whichslide along the base of the magazine housing and may engage tabsprojecting laterally from the staple pusher. Spring means urge thestaple retainer downwardly whereby to confine the staples stored on thestaple guide. The forward side walls of the magazine housing areprovided with elevated portions having forwardly directed recessesformed therein which, when the housing is in closed position, areengaged by a latch member consisting of an apertured plate slidablysupported in the frame and having laterally projecting locking tabsextending through corresponding slots in the frame side walls. The latchmember is spring-urged to the locked position, and the aperture thereinregisters with the pointed end of the cocking member which, whendepressed by the raising of the actuating handle, travels between thefront edge of the aperture and a rearwardly disposed stop, urging thelatch member to its forward open position and releasing the magazinehousing. The magazine housing swings downwardly as does the stapleretaining member, the hooked ends of which engage the staple pushercarrying it to its retracted position and facilitating the loading of astrip of staples. Upon closing of the magazine housing, the staples areurged forward so that the foremost staple is brought against the drivingblade and into its path upon the cocking of the plunger. An aperture isformed in the front bottom wall of the magazine housing and defines astaple exit opening. A

hardened staple exit channel is positioned above this opening andreceives the brunt of the driving cycle.

Reference is now made to the drawings which illustrate a preferredembodiment of the present invention wherein the numerals 12, 12generally designate a pair of laterally spaced, symmertical side wallshaving abutting upper and rear inwardly directed flanges 13, andopposing oval shaped openings 14, in which is positioned a finger grip16 formed of rubber or other suitable material. The side walls 12, whichdefine a supporting frame, have upper and lower projecting portions 17and 18 respectively, which extend into and between side walls 19 of afront channel member 20 abutting said side walls and are secured theretoby means of the suitable screw and spacer assemblies illustrated, whichpass through and are located between corresponding aligned holes formedin the channel side walls 19, and the frame member projections 17 and18. Hinged to the lower rear corner of the frame member is a bottommagazine housing channel 21, having a pair of rear upwardly directedtabs 22, which embrace the lower rear corners of the side walls 12, andhave holes formed therein aligned with corresponding holes formed in theside walls 12, said holes being secured by a suitable post fastener 23.The forward end of channel 21 has a front wall 24, the upper edge ofwhich abuts the front lower edge of the front channel member 20 when themagazine channel is in closed position, and also has a pair of upwardlydirected front tabs 26, whose forward edges fit into the confrontinglower corner edges of channel 20 when the magazine channel 21 is closed.Also formed in the matching portions of the channel walls 19 and tabs26, are recesses 27 and 28 respectively which define a continuous slot.A rectangular opening 29 is formed in the front of the bottom wall ofthe magazine channel 21. An actuating handle 30, having dependinglaterally spaced side walls 32, is hinged to the frame 12 by means of apost screw assembly 33 passing through holes formed in the front portionof the handle side walls 32 and corresponding openings formed in theframe projections 17 and front channel side walls 19, the front portionof the handle side walls embracing the upper portion of the frontchannel side walls 19.

A plunger 26 is vertically slidably disposed in the front channel 20,and includes a ram 37 and a depending driving blade 38. The ram 37 isformed of a sheet of metal and has a front wall 39, side walls orgussets 40, a bottom wall 41 formed of the inwardly directed tabs of thefront wall 39 and gussets 40, and a rear wall formed of a I furtherextension of the front wall tab. The tabs forming the ram bottom wall 41are secured by a centrally located rivet 42. Projecting forwardly fromthe upper portion of the ram front wall 39 are a pair of horizontallyspaced detents 43 which bear against the upper edge of the dependingdriving blade 38 secured to the ram front wall 39 by suitable rivets38a. It should be noted that the plunger is guided by a pair of inwardlydirected ribs 44 formed in the front wall of channel 20 and the forwardvertical edges 46 of the frame wall 12.

Located in the upper end of the channel 20 is a shelf 47 having lateralextensions 48 registering with corresponding slots 49 formed in theupper projecting portions 17, 17 of frame walls 12. Depending centrallyfrom the shelf 47 is a spring-engaging stud having a stepped cylindricalhead 50. A pair of concentric helical compression drive springs 50a, 50bare entrapped between the underside of shelf 47 and the upper face ofthe ram bottom wall 41, urging the plunger 36 to its lowermost oradvanced position. The upper ends of the springs 50a, 50b engage thestud stepped head 50, the springs 50a, 50b, the head 50 and the rivet 42being coaxially disposed. A torsion spring 51, whose arms bear againstthe cross wall of handle 30 and the upper face of shelf 47, is mountedon the bolt 33 and urges the handle 30 to its normal intermediateposition, see Figure 2.

The plunger actuating mechanism includes a lifting lever 52 0f channelshaped cross-section having rearwardly ex? tending. vertical tabsprovided with aligned openings engaging a bolt 52a which is supported bythe frame walls 12and,.in turn, rotatably supportsthe liftinglever 52,.The front end of the lifting lever 52 hasa forwardly projecting arm 53having a convex upper face which engages subv stantially the center ofthe head of the rivet 42. The horizontal wall of the lever 52 has alongitudinal slot.54formed therein. Positioned directly below thelifting lever arm 53 isa cushion assembly consisting of a pair ofsuperimposed plates 56; the lateralendsof which engage and extend intocorresponding horizontal slots 57 formed in. the front channel sidewalls19 flush with theouter margins thereof, and a rubber pad 58 mounted atopthe plates 56, the assembly being secured by a rivet 59. It should benoted that the lifting lever, cushion assembly, driving blade andplunger, and the driving spring mechanism are so dimensioned anddisposed that the lower edge of the blade 38 is. at the levelof. thelower edgeof the magazine channel frontwall 24 when the mechanismisinits normal. at rest position.

In. order to effect the stapledriving stroke, thereis provided. a pairof horizontally spacedparallel fulcrum arms 6.0 which are rotatablysupported between the upper parts of the frame walls. 12 by means of ascrew post 61 passing through aligned holes formed between the ends ofarms 60 and in the frame walls 12. The rear ends. of the arms 6.0 areconnected through a suitable pivot and spacer and by links 63 to a screwpost 64 supported by the side walls of the actuating handle 30. Hingedto and depending from the forward ends of thearms. 60 is. a cockingmember 66, which ispositioned intermediate the arms 60 by means ofSuitable spacers. engaging a pin 67 which registers with holes formed inthe upper part ofcocking member 66 and the forward part of the arms 60.A torsion spring 68, mounted about the post 61, has its arms confinedbetween the lower edges of arms 60 and the. rear edge. of cocking member66 to swing the lower end of. the. member 66 forwardly, The cockingmember 66 terminates at its lower free end in a point defined by afrontv inclined cam edge 69 and a back inclined cam edge 70. Above thefront cam edge 69 and separated therefromby a recessed portion 71defining a hook, is an upwardly, rearwardly in.- clined cam edge 72.

In normal inoperative position, the lower. end. of the cocking member 66passes through the slot 54 in the lifting lever 52, the hook 71 engagingthe front edge of the slot 54. An adjustable triggering element 73 isprovided, having a transverse arm provided with upper and lower steppedbottom edges 74 and 76 respectively, and rearwardly extending fingertabs 77, and is. transversely slidably supported by rectangularvertically extending recesses 78 formed in the frame face forward edges46. A spring member 79, supported on the front channel walls 19 by asuitable post 79a, resiliently retains the member 73 in the recesses 78.While the lower edge of triggering element 73 is illustrated as havingbut two steps, this edge may have a larger number of steps or beinclined, as will be readily understood from the foregoing,

Disposed in and secured to the bottom wall of the magazine channel 21 isa channel-shaped staple guide 80, whose upwardly directed side walls 81have parallel longitudinal slots 82 formed therein. The forward ends ofthe guide. side walls 81 have depending legs 83 which overhang the rearwall of the opening 29 and extend to the lower edge thereof. Anapertured upright tab 84 is positioned at the front end of the stapleguide bottom wall, the other end of which is provided with a rearwardlyextending port-ion terminating in an uprighttab 86 having a horizontalslotformed therein. A pusher member 88, having depending side wallsprovided with longitudinal slots 89, slidably. straddles the guide 80,the slots 89 being aligned withv the guide slots 82. The pusher member88 is also provided with horizontal cross walls, the rear one of whichhas a: depending apertured tab 90. A cross bar 91, having a longitudinaltubular guide opening 92, is positioned in the guide and pusher 88,projecting laterally through and beyond the aligned slots 82 and, 89. Aguide rod 94 passes through the openings in tabs 84, 86 and 90, and thepusher tubular opening 92, and has its flattened rear end upset at tab86 to complete the assembly. Mounted on, and coaxial with, the guide rod94 is a helical compression springv 96 confined between the confrontingfaces of guide tab 86 and pusher tab to urge the pusher 88 to itsadvanced position.

A staple-confining and pusher-retracting member 100 of inverted channel.shape is provided, and has an upper wall 101 and depending side walls102 adapted to straddle thepusher member 88 and nest in the magazinechannel 21. The confining member 100 is hinged to and between the lowerportions of frame walls 12 by means of a screw post 100a passing throughaligned openings formed in upward extensions 103 to the rear portionsof. side walls 102 and corresponding. openings formed in the frame walls12, The front ends of side walls. 102 are provided with forwardlyprojecting Shanks 104 terminate ing in depending rearwardly openhooks106 which ride along the inner longitudinal bottom edges of the channel21 and are adapted to engage the portions of the pusher bar 91projecting beyond the pusher slots 89. Furthermore, a rearwardly flangedupright tab 107 is positioned towards the back edge of. the confiningmember upper wall 101.

A latch or locking member 110 of horizontal platelike configuration isslidably supported at the level. of the recess 27 formed in the frontchannel side walls 19 by means of a plurality of laterally projectingtabs 112, 111, 112 slidably engaging a similar number of slots 113v oflonger extent formed in the frame side walls 12. The centermost tabs 111project through their associated slots 113 beyond the outer faces ofside Walls 12, whereas the front and rear tabs 112 only extend to theplane. of these faces. Formed in the latch member 110, in verticalalignment with the cocking member 66, is alongitudinal rec.- tangularaperture 114, the forward edge of which is provided with. an upwardlyrearwardly inclined tab 116. A stop member 117 is disposed directlyabove the locking member 110 and is supported in fixed position by meansof a pair of laterally extending ears 118 engaging cor.- respondingopenings 118a in the frame side walls 12. The forward edge of the stopmember 117 is provided with a forwardly inclined depending tab 117aprojecting into the locking member aperture 114 at a point intermediatethe ends thereof in lockedposition. A pair of helical tension. springs119 engage at one end openings 120 formed in the rear portion of lockingmember 110 and at the other end spin-121 supported by holes formed inthe upper corners of retaining member side wall extensions 103. Thesprings 119 are normally upwardly deflected from their straight linepath by the retaining member upright 107 and serve the. multiple purposeof urging the locking member 117 to its close position and the confiningmember 100 downwardly and counterclockwise, asseen in- Figure 4.

A channel shaped. staple exit member 122 isformed of a. hardened steeland is disposed at the forward end of the magazine channel 21,registering with the exit aperture 29. The forward wall 123 of the exitmember abuts the inner face of the magazine channel front wall 24 and isprovided at its upper edge with a forwardly projecting lug 126 whichabuts the upper edge .of channel front wall 24 and registers with arecess 127 formed in the lower edge of the front wall of front channelmember 20. The rear portion of the side walls ofv the staple exit memberis directed laterally arcnately outwardlyandforcibly engages theconfronting rear edge of magazinechannel aperture 29. Projectingvertically from the side walls of the exit channel are tabs 128 whichextend above the corresponding edges of the magazine channel side walls.The staple exit member 122 is hardened prior to assembly and, due to itsconfiguration, distortion will be outward which is favorable since apreloaded condition is set up when it is assembled into forward end ofmagazine channel 21. The curved end faces of the member 122 abutting therear edge of aperture 29 secures it therein, correcting an inwarddistortion that might manifest itself after the heat treating process.In the exceptional case, where the distortion of the side walls ofmember 122 is laterally outward, then the side walls of the magazinechannel 21 will forcibly engage the exit member side walls suitably,preloading the same. Moreover, the abutting faces of the walls 24 and123 are secured by a tack weld. It should be noted that the forwardvertical edges of the staple guide 81 are spaced from the inner face ofthe wall 123 of exit member 122 a distance sufficient to permit easypassage of the driving blade 38.

Considering now the operation of the improved stapling gun; in order toload the gun, the actuating handle 30 is raised in the direction of thearrow, Figure 6, causing the fulcrum arm 60 to rotate counterclockwise.The point of the depending cocking member 66 is thereby forceddownwardly into the aperture 114 of the locking member 110. The lockingmember lower forward cam edge 69 engages the tab 116 and the rear camedge 70 engages the stop tab 117 urging the locking member 110 forwardand the locking tabs 111 from the close position in the recesses 28 totheir open position out of these recesses and into the adjacent recesses27. The springs 119, acting through the retaining member 100, swing themagazine channel 21 to its fully open position as seen in Figure 4, thelower edges of hooks 106 riding along the bottom Wall of the magazinechannel 21. As the magazine channel 21 is swung outwardly, the hooks 106engage the laterally projecting portions of the pusher bar 91withdrawing the staple pusher member 88 to its retracted position andcompressing the feed spring 96. A strip of staples may then be placed onthe staple guide 80, and the magazine channel thereafter swung to itsclosed position, the locking tabs engaging the locking recesses 28. Thehooked ends 106 of the retaining member 100 are thus returned to theforward end of the magazine channel 21, allowing the pusher member 88 toslide forward, engaging the rear staple of the strip and, by virtue ofthe spring 96, urging the strip of staples forward and the foremoststaple against the inner face of the driving blade 38. The springs 119,acting on the upright 107, urge the confining member 100 downwardly,which maintains a pressure on the top side or bridge of the staples whenloaded on the staple guide and thereby greatly inhibits the jamming ofthe staples.

In performing the stapling operation, the actuating handle 30 is presseddownwardly toward the frame member 12, thereby rotating the fulcrum arms60 clockwise, as seen in Figure 3, and raising the cocking member 66.The hooked portion 71 of the cocking member 66 passing through liftinglever slot 54, engages the lower face of the lifting lever 52 androtates the lifting lever 52 clockwise about pin 52a. The forward edge53 of the lifting lever 52, acting on the rivet head 42, raises theplunger 37 and, as the lower edge of the driving blade 38 is elevatedabove the level of the strip of staples, the foremost staple is advancedinto the vertical path of the driving blade 38 under the urging ofspring 96. In the raising of the plunger 36, the energy storing springs51 are compressed and loaded. As the fulcrum arm 60 is rotated clockwiseand the cocking member 66 thereby raised, the forward upper cam edge 72of the cocking member comes into contact with and engages the lower edge74 or 76, as the case may be, of the triggering element 73. Thetriggering element lower edge, acting on the cam edge 72 (see Figure 3),swings the cocking lever 66 rearwardly as it is raised until the forwardedge of the hook portion thereof 8 is retracted beyond the forward edgeof the slot 54 in the lifting lever 52, releasing the lifting lever 52and the plunger 36. The loaded spring is thus permitted to expand andsend the plunger forcibly downwardly, the blade 38 engaging the bridgeof the staple in its path, shearing it from the cohered strip anddriving it home. The shock of the descending plunger and lifting leveris cushioned by the rubber pad 58.

After the completion of the staple driving stroke, the handle 30 isreleased and the entire mechanism returned to the starting position, asshown in Figure 2, being urged thereto by the springs 51 and 68.

It should be pointed out that when the triggering element is in theposition shown in Figure 7, the higher stepped edge 74 engages thecocking member cam surface 72 and releases the plunger when it has beenraised to a greater height than when the triggering element is in theposition shown in Figure 8 and the lower edge 76 engages the cam surface72. Since, in the former case, more compression is imparted to thesprings 51 and hence more energy, a heavier driving stroke is effectedwhen the triggering element is in the position illustrated in Figure 7,and a lighter stroke is effected when the triggering element is in theposition shown in Figure 8. It is also important to observe that sincethe lifting lever 52 engages the ram 37 at a point and in a directioncolinear with the axis of the compression springs 51, there is a minimumof torque and hence an increase in energy efficiency and a decrease inthe frictional wear due to the wasted energy dissipated as a result ofthis torque.

While there has been described and illustrated a preferred embodiment ofthe present invention, it is apparent that numerous alterations andomissions may be made without departing from the spirit thereof.

I claim:

1. A stapling device comprising a body member, a staple magazine mountedon the lower portion of said body member and movable relative theretobetween a closed position and an open position permitting access to theinterior of said magazine, a latch element movable between lock andunlock positions and normally engaging said body member and said staplemagazine and releasably locking said staple magazine in closed position,a staple driving mechanism disposed in said body member, a handlemounted on said body member and adapted to actuate said staple drivingmechanism when moved between first and second predetermined positionsand a lost motion mechanism providing engagement between said handle andsaid latch member and urging said latch member to unlock position whensaid handle is moved to a third predetermined position outside the pathbetween said first and second predetermined positions.

2. A stapling device in accordance with claim 1, wherein said staplemagazine is hinged to said body member and is provided with a latchingrecess and said latch element is slidably supported in said body memberand movable into and out of engagement with said latching recess todefine lock and unlock positions respectively.

3. A stapling device in accordance with claim 2, including spring meansurging said latching element into lock position.

4. A stapling device in accordance with claim 2, wherein said handle ishinged to said body member and is rotatable between said predeterminedpositions, said third predetermined position being above said first andsecond predetermined positions.

5. A stapling device comprising a body member, a staple magazine hingedto said body member and having a recess formed therein and being movablebetween open and closed positions, a latching element slidably supportedon said body member and movable into and out of engagement with saidrecess when said staple magazine is in closed position to define lockand unlock positions, spring means urging said latch element into lockposition, a staple driving mechanism mounted in said body member, ahandle hinged to said body member and adapted to actuate said stapledriving mechanism and unlocking means adapted to move said latchingelement into unlock position when said handle is raised above apredetermined point relative to said body member.

6. A stapling device in accordance with claim 5, wherein said latchingelement comprises a horizontal plate having an opening formed thereinwhich has front and rear edges, and there is provided a stop membermounted in said body member adjacent said opening, and said unlockingmeans includes a lever pivoted at a point between its ends to said bodymember, one end of said lever being linked to said actuating handle andan arm depending from the other end of said lever and terminating in atapered end adapted to register with said latch element opening andengage an edge thereof and said stop member.

7. A staple driving gun comprising a body member, a staple driveactuating handle hinged to the upper portion of said body member, astaple magazine hinged to the lower portion of said body member andprovided with a catch element, a latch member disposed in the lowerportion of said body member and movable into and out of engagement withsaid catch element, and a lost motion mechanism providing engagementbetween said latch member and said actuating handle and urging saidlatch member out of engagement with said catch element when saidactuating handle is moved to a predetermined position.

8. A staple driving gun in accordance with claim 7,

wherein there is provided spring means urging said magazine to its openposition.

9. A staple driving gun in accordance with claim 7, wherein saidactuating handle is movable from a normal intermediate positiondownwardly to efiect a staple driving stroke and upwardly from saidintermediate position to urge said latch member to its unlockedposition, and spring means are provided to normally urge said latchmember to its lock position.

10. A staple driving gun in accordance with claim 7, wherein there areprovided a stop member horizontally spaced from a confronting edge ofsaid latch member and a depending arm movable by said handle and invertical alignment with the space between said confronting edge and saidstop member and terminating at its lower end in a wedge-shaped portionadapted to register with said space upon the raising of said handle tourge said latch member to its unlock position.

11. A staple driving gun in accordance with claim 10, wherein there areprovided a staple driving means, spring means urging said driving meansto its advanced position, said depending arm being in releasableengagement with said driving means and adapted to raise said drivingmeans upon depression of said actuating handle, and a triggering elementurging said arm out of engagement with said driving means upon saiddriving means being raised to a predetermined level.

No references cited.

